1. Field of the Invention
The present invention relates to a switching power supply system for automatically regulating circuit operating power and the method thereof, and particularly, to a switching power supply system, which is adapted to a computer system and is capable of automatically regulating circuit operating power, and the method thereof.
2. Description of the Related Art
Referring to FIG. 1, a schematic block diagram of a conventional switching power supply system is shown. The switching power supply system utilizes pulse width modulation (PWM) technology. Specifically, a PWM control circuit 18, which is connected to a DC converter 16, generates a control signal to control switching of a power switch in the DC converter 16. The DC converter 16 converts power from a dual power system (DPS) unit 17 connected to the DC converter 16 into DC power and supplies the DC power to the computer system through a filter network 12.
According to conventional technology employed in a computer system, the number of the dual power system (DPS) units that are turned on upon turning on the computer system is fixed and cannot be changed. Consequently, the number of the dual power system (DPS) units that are turned on cannot be changed in response to any current load variations resulting from execution of any software by any type of central processing unit (CPU), environmental variations inside/outside the housing and voltage variations caused by the power supply or by the load. Therefore, temperature variation of a single pulse-width modulation PWM, output current amount and power consumption of the power system for the central processing unit (CPU) are constant and thus the efficiency cannot be maximized in accordance with the changing environment.